US4609593A - Magnetic recording medium - Google Patents

Magnetic recording medium Download PDF

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Publication number
US4609593A
US4609593A US06/630,898 US63089884A US4609593A US 4609593 A US4609593 A US 4609593A US 63089884 A US63089884 A US 63089884A US 4609593 A US4609593 A US 4609593A
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US
United States
Prior art keywords
magnetic
thin layer
atom
recording medium
magnetic thin
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Expired - Fee Related
Application number
US06/630,898
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English (en)
Inventor
Keishi Nakashima
Takashi Hatanai
Koichi Mukasa
Yutaka Shimada
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Alps Alpine Co Ltd
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Alps Electric Co Ltd
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Assigned to ALPS ELECTRIC CO., LTD., A CORP. OF JAPAN reassignment ALPS ELECTRIC CO., LTD., A CORP. OF JAPAN ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HATANAI, TAKASHI, MUKASA, KOICHI, NAKASHIMA, KEISHI, SHIMADA, YUTAKA
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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/64—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent
    • G11B5/66—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent the record carriers consisting of several layers
    • G11B5/672—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent the record carriers consisting of several layers having different compositions in a plurality of magnetic layers, e.g. layer compositions having differing elemental components or differing proportions of elements
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/922—Static electricity metal bleed-off metallic stock
    • Y10S428/9265—Special properties
    • Y10S428/928—Magnetic property
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12465—All metal or with adjacent metals having magnetic properties, or preformed fiber orientation coordinate with shape
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
    • Y10T428/12556—Organic component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
    • Y10T428/12556—Organic component
    • Y10T428/12562—Elastomer
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
    • Y10T428/12556—Organic component
    • Y10T428/12569—Synthetic resin
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
    • Y10T428/12597—Noncrystalline silica or noncrystalline plural-oxide component [e.g., glass, etc.]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12826—Group VIB metal-base component
    • Y10T428/12847—Cr-base component
    • Y10T428/12854—Next to Co-, Fe-, or Ni-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y10T428/12931—Co-, Fe-, or Ni-base components, alternative to each other

Definitions

  • This invention relates to a magnetic recording medium for perpendicular magnetic recording using a soft magnetic material of high permeability composed of an amorphous cobalt-base alloy.
  • the foregoing 1st magnetic thin layer has a role of forming a part of a magnetic pass in the case of magnetizing the 2nd magnetic thin layer and is required to possess a low coercive force and a high permeability as well as a high saturation magnetic flux density.
  • the 2nd magnetic thin layer is required to possess an anisotropy in the perpendicular direction of the layer.
  • cobalt-chromium system alloys such as cobalt-chromium binary alloy and a ternary alloy composed of cobalt, chromium, and a third metal such as rhodium.
  • permalloy is usually used for the 1st magnetic thin layer but permalloy does not have a sufficient permeability and saturation magnetic flux density. Furthermore, permalloy is inferior in so-called affinity in magnetic properties with the 2nd magnetic thin layer composed of the foregoing cobalt-chromium system alloy.
  • the 2nd magnetic thin layer composed of the cobalt-chromium system alloy is formed on the 1st magnetic thin layer composed of permalloy having a face centered cubic lattice in the crystal structure, the formation of a hexagonal system in crystal structure of the thin layer of the cobalt-chromium system alloy is obstructed by the influence of the thin layer of permalloy disposed under the cobalt-chromium system alloy thin layer (in particular, owing to the thinness of the 2nd magnetic thin layer), whereby the excellent perpendicular anisotropy, which is a feature of a cobalt-chromium system alloy, cannot sufficiently be attained.
  • the conventional magnetic recording medium having the foregoing layer structure has a fault that even if a cobalt-chromium system alloy having excellent magnetic characteristics is used for the 2nd magnetic thin layer, the excellent properties of the alloy cannot sufficiently be utilized.
  • the object of this invention is to increase the recording density and the reproducing density of a magnetic recording medium for a perpendicular magnetic recording system.
  • a magnetic recording medium comprising a base material, a 1st magnetic thin layer formed on the surface of the base material, and a 2nd magnetic thin layer having a perpendicular anisotropy and formed on the surface of the 1st magnetic thin layer, said 2nd magnetic thin layer being magnetized in the thickness direction, wherein said 1st magnetic thin layer is composed of a cobalt-based ternary amorphous alloy containing small amounts of hafnium and tantalum.
  • FIG. 1 is characteristic graph showing the relation between the Hf content in Co-Hf-Ta system amorphous alloys and various magnetic properties
  • FIG. 2 is a characteristic graph showing the relation between the Ta content in the foregoing alloys and various magnetic properties
  • FIG. 3 is magnetic characteristic curves of the foregoing alloy and a comparison alloy at each frequency
  • FIG. 4 is a schematic view for explaining the state of using the magnetic recording medium of this invention.
  • a crystal glass is used as a base plate and pellets of hafnium and pellets of tantalum (each pellet having 10 mm ⁇ 10 mm in area and 5 mm in thickness) are alternately disposed on a cobalt disk (101.6 mm in diameter and 5 mm in thickness) radially from the center of the disk, whereby the composition of the alloy formed on the base plate by sputtering can be changed by controlling the number of the pellets on the target.
  • a chamber containing the foregoing system is evacuated to high vacuum of lower than 1 ⁇ 10 -6 Torr and sputtering is performed in an argon gas atmosphere at a high frequency electric power of 2.0 watts/cm 2 to form a cobalt-base Co-Hf-Ta ternary amorphous alloy on the base plate.
  • the amorphous alloys having various compositions formed as above described are used for various property tests as set forth hereinafter.
  • FIG. 1 is a magnetic characteristic graph in the case of changing the content X of hafnium in the alloy shown in the alloy composition table shown below while always keeping the content Y of tantalum in the alloys at 4.5 atom%.
  • the curve Bs shows a saturation magnetic flux density
  • the curve ⁇ e a permeability in the sparingly magnetizable axis direction at a frequency of 1 MHz
  • the curve of Hc a coercive force in the sparingly magnetizable axis direction.
  • the Co-Ta binary alloy containing no Hf has high Bs but is too high in Hc and low in ⁇ e .
  • Hc greatly decreases, while ⁇ e increases in contrast with this.
  • Hc becomes high and ⁇ e becomes low.
  • Bs tends to decrease with the increase of the content of Hf although the decreasing extent is not so extreme.
  • the content X of Hf be in the range of from 1 atom% to 5 atom%, preferably from 1.5 atom% to 3 atom%. This is also true when the content Y of Ta is changed to some extent.
  • FIG. 2 is a magnetic characteristic graph showing the case of changing the content Y of Ta in the alloy shown in the foregoing alloy composition table while always keeping the content X of Hf in the alloy at 2.2 atom%.
  • the content Y of Ta be in the range of from 4 to 10 atom%, preferably from 6 to 8 atom%.
  • FIG. 3 is a graph showing ⁇ e of a ternary amorphous alloy composed of Co (93.3 atom%), Hf (2.2 atom%), and Ta (4.5 atom%) (Curve A) and ⁇ e of a binary amorphous alloy composed of Co (97.8 atom%) and Hf (2.2 atom%) (Curve B) at each frequency.
  • the soft magnetic material of this invention always has a high permeability at each frequency and shows stable characteristics in a wide frequency range.
  • a Co-Hf-Ta ternary alloy shows a high anisotropic magnetic field in the thin layer thereof immediately after the formation thereof by sputtering.
  • a method of heat-treating the ternary amorphous alloy thin layer formed as a principal magnetic pole in a rotating magnetic field is effective.
  • the conditions for the heat treatment in the rotating magnetic field are selected from a rotation speed of 10 to 20 r.p.m., a magnetic field intensity of higher than 100 O e and a treatment time of longer than 3 hours.
  • the anisotropic magnetic field (Hk) can be reduced to about 4 O e .
  • FIG. 4 is a schematic view explaining a state of using the magnetic recording medium using the foregoing soft magnetic material.
  • a Co-Hf-Ta ternary amorphous alloy composed of 93.3 atom% Co, 2.2 atom% Hf, and 4.5 atom% Ta is formed on the surface 1 of a base material composed of a synthetic resin such as polyester, polyimide, etc., or an anodically oxidized aluminum plate by sputtering to provide a 1st magnetic thin layer 2.
  • a Co-Cr binary alloy thin layer composed mainly of Co having added thereto a small amount of Cr is formed on the surface of the 1st magnetic thin layer 2 by sputtering to provide a 2nd magnetic thin layer 3.
  • the thicknesses of these thin layers are about 0.3 ⁇ m.
  • a tape-form or disk-form magnetic recording medium is formed from the foregoing material composed of a base material 1, the 1st magnetic thin layer 2, and the 2nd magnetic thin layer 3.
  • the foregoing magnetic thin layers 2 and 3 may be formed on both surfaces of the base material 1.
  • a principal magnetic pole 5 and an auxiliary magnetic pole 6 are disposed with the magnetic recording medium between them.
  • the principal magnetic pole 5 has a thickness of about 1 ⁇ m and is formed on a non-magnetic base plate 4 composed of a glass or a polyimide resin.
  • a coil 7 is coiled around the auxiliary magnetic pole 6 at a definite turn. When a signal electric current is passed through the coil 7 to magnetize the principal magnetic pole 5 from the side of the auxiliary magnetic pole 6, a strong perpendicular magnetic field is generated near the end of the principal magnetic pole 5, whereby the magnetic thin layers 2 and 3 near the end of the principal magnetic pole 5 are magnetized in the thickness direction of the layers and the data are recorded in the 2nd magnetic thin layer 3.
  • the 1st magnetic thin layer 2 contributes to constitute a part of the magnetic pass at the case of magnetically recording the data in the 2nd magnetic recording thin layer 3.
  • a soft magnetic material having a low coercive force and a high permeability can be obtained without reducing a saturation magnetic flux density too much and by using the foregoing soft magnetic material as the 1st magnetic thin layer of a magnetic recording medium composed of a base material, a 1st magnetic thin layer, and a 2nd magnetic thin layer having a perpendicular anisotropy and formed on the magnetic thin layer, the following excellent effects are obtained.
  • the ternary amorphous alloy forming the 1st magnetic thin layer has low coercive force and high permeability and saturation magnetic flux density as well as has very similar magnetic characteristics to those of a cobalt-chromium system alloy forming the 2nd magnetic thin layer, whereby the cobalt-chromium alloy formed on the 1st magnetic thin layer can exhibit the excellent magnetic anisotropy thereof as it is.
  • the magnetic recording medium of this invention has excellent recording and reproducing characteristics and in the magnetic recording medium of this invention the thickness of the 2nd magnetic thin layer can be reduced as thin as possible.

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  • Magnetic Record Carriers (AREA)
  • Thin Magnetic Films (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
US06/630,898 1983-07-16 1984-07-16 Magnetic recording medium Expired - Fee Related US4609593A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP58128718A JPS6021508A (ja) 1983-07-16 1983-07-16 磁気記録媒体
JP58-128718 1983-07-16

Publications (1)

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US4609593A true US4609593A (en) 1986-09-02

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US06/630,898 Expired - Fee Related US4609593A (en) 1983-07-16 1984-07-16 Magnetic recording medium

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US (1) US4609593A (ja)
JP (1) JPS6021508A (ja)
KR (1) KR890003038B1 (ja)
DE (1) DE3426178A1 (ja)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4786553A (en) * 1986-03-28 1988-11-22 Hitachi, Ltd. Magnetic recording medium
GB2216544A (en) * 1988-03-23 1989-10-11 Alps Electric Co Ltd Refractory amorphous alloys
US20100312891A1 (en) * 2009-06-05 2010-12-09 Microsoft Corporation Utilizing affinity groups to allocate data items and computing resources
US20100312809A1 (en) * 2009-06-05 2010-12-09 Microsoft Corporation Geographic co-location service for cloud computing

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4731300A (en) * 1985-03-07 1988-03-15 Victor Company Of Japan, Ltd. Perpendicular magnetic recording medium and manufacturing method thereof
DE3610431A1 (de) * 1985-03-28 1986-10-02 Victor Company Of Japan, Ltd., Yokohama, Kanagawa Quermagnetisierungsaufzeichnungsmedium
US4798765A (en) * 1985-03-28 1989-01-17 Victor Company Of Japan Ltd. Perpendicular magnetic recording medium

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5850639A (ja) * 1981-09-18 1983-03-25 Ricoh Co Ltd 垂直磁化記録媒体
JPS5855557A (ja) * 1981-09-29 1983-04-01 Takeshi Masumoto 鉄族系非晶質合金
JPS5979434A (ja) * 1982-10-27 1984-05-08 Seiko Epson Corp 磁気記録媒体
JPS5998322A (ja) * 1982-11-29 1984-06-06 Alps Electric Co Ltd 磁気記録媒体

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5891B2 (ja) * 1977-09-30 1983-01-05 俊一 岩崎 磁気記録媒体
JPS5819474A (ja) * 1981-07-27 1983-02-04 Victor Co Of Japan Ltd 機能性メツキ膜の製法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5850639A (ja) * 1981-09-18 1983-03-25 Ricoh Co Ltd 垂直磁化記録媒体
JPS5855557A (ja) * 1981-09-29 1983-04-01 Takeshi Masumoto 鉄族系非晶質合金
JPS5979434A (ja) * 1982-10-27 1984-05-08 Seiko Epson Corp 磁気記録媒体
JPS5998322A (ja) * 1982-11-29 1984-06-06 Alps Electric Co Ltd 磁気記録媒体

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4786553A (en) * 1986-03-28 1988-11-22 Hitachi, Ltd. Magnetic recording medium
GB2216544A (en) * 1988-03-23 1989-10-11 Alps Electric Co Ltd Refractory amorphous alloys
US4936929A (en) * 1988-03-23 1990-06-26 Alps Electric Co., Ltd. Refractory amorphous Co-Ta-Hf alloy
GB2216544B (en) * 1988-03-23 1991-04-17 Alps Electric Co Ltd Refractory amorphous alloys
US20100312891A1 (en) * 2009-06-05 2010-12-09 Microsoft Corporation Utilizing affinity groups to allocate data items and computing resources
US20100312809A1 (en) * 2009-06-05 2010-12-09 Microsoft Corporation Geographic co-location service for cloud computing
US8577892B2 (en) * 2009-06-05 2013-11-05 Microsoft Corporation Utilizing affinity groups to allocate data items and computing resources
US10127295B2 (en) 2009-06-05 2018-11-13 Microsoft Technolofy Licensing, Llc Geographic co-location service for cloud computing

Also Published As

Publication number Publication date
JPH037125B2 (ja) 1991-01-31
DE3426178C2 (ja) 1988-06-01
DE3426178A1 (de) 1985-01-31
KR890003038B1 (ko) 1989-08-19
JPS6021508A (ja) 1985-02-02
KR850001597A (ko) 1985-03-30

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